Switch to prefixed IDs and tell agents which Mac a message came from

internal/store/blob.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"g.fc.run/ai/byre/internal/api"
+	"g.fc.run/ai/byre/internal/ids"
 )
 
 const MaxBlobBytes = 5 << 20
@@ -22,7 +23,7 @@ var ImageTypes = map[string]bool{
 
 func (s *Store) CreateBlob(ctx context.Context, contentType string, data []byte, actor string) (api.Blob, error) {
 	b := api.Blob{
-		Id:          NewID(),
+		Id:          ids.New(ids.Blob),
 		ContentType: contentType,
 		CreatedBy:   actor,
 		CreatedAt:   time.Now().UTC(),